Hayes said himself that his fitness stats were up top end in current Celtic squad.
His leg break was just that. A leg break. Not anything that could would affect his long term fitness etc. such as ligaments etc. so that is a shite gripe as well.
His desire well never go away imo. He’s not that type of player to lose that/give up. He’s more the type that will give 100% until his body simply cannot.
Hayes is still a great signing for us & would be for plenty sides still.